Hypoxia-induced changes in shivering and body temperature

1987 ◽  
Vol 62 (6) ◽  
pp. 2477-2484 ◽  
Author(s):  
H. Gautier ◽  
M. Bonora ◽  
S. A. Schultz ◽  
J. E. Remmers
Keyword(s):  
Central Nervous System ◽  
Body Temperature ◽  
Room Temperature ◽  
Co2 Concentration ◽  
Hypoxic Conditions ◽  
O2 Concentration ◽  
The Central Nervous System ◽  
Induced Changes ◽  
Maintain Body Temperature ◽  
Ambient Hypoxia

Experiments were carried out on conscious cats to evaluate the general characteristics and modes of action of hypoxia on thermoregulation during cold stress. Intact and carotid-denervated (CD) conscious cats were exposed to ambient hypoxia (low inspired O2 fraction) or CO hypoxia in prevailing laboratory (23–25 degrees C) or cold (5–8 degrees C) environments. In the cold, both groups promptly decreased shivering and body temperature when exposed to either type of hypoxia. Small increases in CO2 concentration reinstituted shivering in both groups. At the same inspired concentration of O2, CD animals decreased shivering and body temperature more than intact cats. While this difference resulted, in part, from a lower alveolar PO2 in CD cats, a difference between intact and CD cats was apparent when the two groups were compared at the same alveolar PO2. During more prolonged hypoxia (45 min), shivering returned but did not reach normoxic levels, and body temperature tended to stabilize at a hypothermic value. Exposure to various levels of hypoxia produced graded suppression of shivering, with the result that the change in body temperature varied directly with inspired O2 concentration. Hypoxia appears to act on the central nervous system to suppress shivering and sinus nerve afferents appear to counteract this direct effect of hypoxia. In intact cats, this counteraction appears to be sufficient to maintain body temperature under hypoxic conditions at room temperature but not in the cold.

Chromatolysis and vacuolation of specific diencephalic nuclei induced by acute pyrexia

1958 ◽  
Vol 196 (1) ◽  
pp. 33-35 ◽  
Author(s):  
Harold Brody ◽  
Simon Rodbard
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Temperature ◽  
Radiant Heat ◽  
High Body ◽  
The Central Nervous System

To determine the effects of high body temperature upon cells of the central nervous system, chicks were exposed to radiant heat. An increase in body temperature 3°C above normal resulted in chromatolysis and vacuolation in the cells of the nucleus rotundum, the nucleus entopeduncularis inferior and nucleus anterior medialis of the hypothalamus. A decrease in body temperature 15°C below normal had no effect upon these cells. It is suggested that the nuclei affected by the induced acute pyrexia may be involved in sensing and responding to the specific thermal overload.

Antipyretic effect of arginine vasotocin in toads

2000 ◽  
Vol 278 (6) ◽  
pp. R1408-R1414 ◽  
Author(s):  
K. C. Bicego-Nahas ◽  
A. A. Steiner ◽  
E. C. Carnio ◽  
J. Antunes-Rodrigues ◽  
L. G. S. Branco
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Temperature ◽  
Thermal Gradient ◽  
Arginine Vasotocin ◽  
Antipyretic Effect ◽  
The Central Nervous System ◽  
Preferred Body Temperature ◽  
Toad Bufo

Arginine vasotocin (AVT) is a nonmammalian analog of the mammalian hormone arginine vasopressin (AVP). These peptides are known for their antidiuretic and pressor effects. More recently, AVP has been recognized as an important antipyretic molecule in mammals. However, no information exists about the role of AVT in febrile ectotherms. We tested the hypothesis that AVT is an antipyretic molecule in the toad Bufo paracnemis. Toads equipped with a temperature probe were placed in a thermal gradient, and preferred body temperature was recorded continuously. A behavioral fever was observed after lipopolysaccharide (LPS) was injected systemically (200 μg/kg). Systemically injected AVT (300 pmol/kg) alone caused no significant change in body temperature, but abolished LPS-induced fever. Moreover, a smaller dose of AVT (10 pmol/kg), which did not affect LPS-induced fever when injected peripherally, abolished fever when injected intracerebroventricularly. We therefore conclude that AVT plays an antipyretic role in the central nervous system, by means of behavior, in an ectotherm, a fact consistent with the notion that AVT/AVP elicits antipyresis by reducing the thermoregulatory set point.

scholarly journals The impact of a binary catalyst system «tereftal + ascorbic acid» on the central nervous system

2017 ◽  
Vol 16 (2) ◽  
pp. 42-49
Author(s):  
N. P. Ermakova ◽  
S. S. Trofimov ◽  
N. Y. Kulbachevskaya ◽  
O. I. Konyaeva ◽  
V. M. Bukhman ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Ascorbic Acid ◽  
Nervous System ◽  
Body Temperature ◽  
Open Field ◽  
Catalytic System ◽  
Catalyst System ◽  
Emotional Status ◽  
The Central Nervous System ◽  
Binary Catalyst

Introduction. Neurotoxicity is one of the specific systemic complications of anticancer chemotherapy. Detection in experimental animals complications of psychotropic or neurotropic action of the new drug is one of the most difficult challenges of preclinical toxicology. Preclinical toxicological study of the effect of a binary catalyst system «tereftal + ascorbic acid» on the central nervous system (CNS). Objective. The prediction of toxic effects of binary catalytic system in clinical application in patients. Materials and methods. The study was conducted on 300 male mice hybrids (CBA х C57 Bl/6J) F1. Have terephtal - russian drug. A binary catalyst system was injected intravenously once at close to the maximum tolerated dose - 50 mg/kg tereftal + 110 mg/kg ascorbic acid and in therapeutic dose - 20 mg/kg tereftal + 44 mg/kg ascorbic acid. The obtained data were compared with a control animal treated with saline solution and with the data of animals treated with one tereftal and one ascorbic acid in equivalent doses. To assess neurotoxicity tests used standard neuropharmacological screening. An assessment of emotional status, muscle tone were undertaken. Behavior was evaluated in the tests «open field» and «aggression». We evaluated the response to pain stimulation, the change in rectal body temperature. Higher integrative brain functions were investigated on the model of the conditioned reflex of passive avoidance. Estimated effect on convulsive readiness of the CNS. Results. The catalytic system changed the general condition of the animals. This was manifested, on the one hand, in the suppression of their overall activity (sluggishness, inactivity until weakness, muscle relaxation, the lowering side, the slowing of breathing), the other - to increase their excitability (when in group, some animals adopted a characteristic aggressive stands, in some cases seizures). These animals were observed exophthalmos, the appearance of the position «frog», posture «praying mouse», the desire to hide. The inhibitory effect of the catalytic system was dose-dependent. Observed inhibition of various forms of behavior, emotional status, decrease in body temperature and pain sensitivity, in the test for aggression - reducing the number of fights, in open field test - locomotor activity suppression. Spontaneous seizures in the provocation corazol binary catalytic system was not strengthened. Conclusion. The obtained data allow to predict toxic effects from the CNS during clinical use of binary catalytic system «tereftal + ascorbic acid»: total confusion, lethargy, physical inactivity, decrease in body temperature, increased anxiety and aggression and, in very rare cases, the occurrence of seizures.

Recognizing Radiation-induced Changes in the Central Nervous System: Where to Look and What to Look For

Radiographics ◽  
2021 ◽  
Vol 41 (1) ◽  
pp. 224-248
Author(s):  
Masaki Katsura ◽  
Jiro Sato ◽  
Masaaki Akahane ◽  
Toshihiro Furuta ◽  
Harushi Mori ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Radiation Induced ◽  
The Central Nervous System ◽  
Induced Changes

A combined pre- and post-embedding double labeling in the central nervous system with good tissue preservation

1991 ◽  
Vol 49 ◽  
pp. 276-277
Author(s):  
A.M. Milroy ◽  
D.D. Ralston
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Double Labeling ◽  
Highly Sensitive ◽  
The Central Nervous System

Multiple labeling at the electron microscopic level is routinely done in various parts of the central nervous system. We demonstrate that the pre-embedding tetramethylbenzidine (TMB) reaction for visualizing horseradish peroxidase (HRP) of Olucha and the slow osmication of Henry combined with a post-embedding nonetching immunogold method will also preserve good ultrastructure. Furthermore, the post-embedding immunocytochemistry of some neurotransmitters, i.e. gammaaminobutyric acid (GABA), can be done months after the tissue has been reacted for HRP and embedded in regular epon.Pre-embedding histochemistry:The use of TMB as a chromagen for the demonstration of neuronally transported HRP has both the advantage of being highly sensitive and of producing very specific needle-like crystals. Olucha et al demonstrated that one could further stabilize this reaction product with amonium heptamolybdate. Unfortunately the next step, fixation with regular osmium tetroxide, often resulted in the loss of the reaction product. However, the slow osmication with a lower pH (5.5) in the phosphate buffer at room temperature as recommended by Henry et al prevented this loss, and at the same time resulted in well preserved ultrastructure.

Fixation of the Central Nervous System by Perfusion With Aldehydes and its Effect on the Extracellular Space as seen by Electron Microscopy

1967 ◽  
Vol 2 (3) ◽  
pp. 377-386
Author(s):  
PATRICIA V. JOHNSTON ◽  
BETTY I. ROOTS
Keyword(s):  
Electron Microscopy ◽  
Central Nervous System ◽  
Nervous System ◽  
Extracellular Space ◽  
Room Temperature ◽  
Lateral Geniculate Body ◽  
Cross Linking ◽  
Apparent Lack ◽  
The Central Nervous System ◽  
Striking Change

Rat brains fixed by perfusion with glutaraldehyde and prepared for electron microscopy under certain conditions showed an abundance of very closely apposed or completely fused surface membranes in some areas. This apparent lack of extracellular space was most consistently observed in the lateral geniculate body and the superior colliculus and less consistently in the cerebellum and parietal cortex. Lowering the temperature of the perfusate from body temperature (38-39 °C) to room temperature (19-20 °C) and/or lowering the pressure at which it was delivered (from 140 to 70 cm of water) led to the appearance of more extracellular space. A striking change in the amount of extracellular space was observed when ethanol was used for dehydrating the samples instead of acetone. When ethanol was employed a space of approximately 100 Å was seen between most cellular elements, whereas acetone dehydration led to an abundance of closely apposed or fused surface membranes. It is suggested that if glutaraldehyde acts by cross-linking proteins in apposing membranes, this reaction is more effectively completed in the presence of acetone and that this may be due to depolymerization of glutaraldehyde by the solvent. It is also suggested that the variation in the amount of extracellular space seen in brains fixed by perfusion with aldehydes may reflect real differences in distances between membranes at the time of fixation.

Neonatal hypothermia

2020 ◽  
pp. 23-30
Author(s):  
Lev Shkondin
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Temperature ◽  
Medical Care ◽  
Axillary Temperature ◽  
The Central Nervous System ◽  
Neonatal Hypothermia

Hypothermia in newborns is a violation of heat metabolism, which is accompanied by a decrease in body temperature below 36.4 °C, manifested by polysystemic disorders of the central nervous system, cardiovascular, respiratory and other systems of the infant's body. Hypothermia occurs with a decrease in the axillary temperature in the newborn lower than 36.4 °C. It can develop rapidly, within 1–2 minutes, with a loss of temperature at a speed of 0.4 °C. It is a serious complication that requires quick and intensive correction; it can lead to irreversible changes, and even death, without the necessary medical care.

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